#ifndef COMMON_LOCAL_DATE_TIME_H_
#define COMMON_LOCAL_DATE_TIME_H_

#include <fermat/common/date_time.h>


namespace fermat {

/************************************************
* This class represents an instant in local time
* (as opposed to UTC), expressed in years, months, days, 
* hours, minutes, seconds and milliseconds based on the 
* Gregorian calendar.
*
* In addition to the date and time, the class also 
* maintains a time zone differential, which denotes
* the difference in seconds from UTC to local time,
* i.e. UTC = local time - time zone differential.
*
* Although LocalDateTime supports relational and arithmetic
* operators, all date/time comparisons and date/time arithmetic
* should be done in UTC, using the DateTime or Timestamp
* class for better performance. The relational operators
* normalize the dates/times involved to UTC before carrying out
* the comparison.
*
* The time zone differential is based on the input date and
* time and current time zone. A number of constructors accept
* an explicit time zone differential parameter. These should
* not be used since daylight savings time processing is impossible
* since the time zone is unknown. Each of the constructors
* accepting a tzd parameter have been marked as deprecated and
* may be removed in a future revision.
************************************************************/
class  LocalDateTime {
public:
	/*********************************************************
	* Creates a LocalDateTime with the current date/time 
	* for the current time zone.
	**********************************************************/
	LocalDateTime();

	/********************************************************
	* Creates a LocalDateTime for the given Gregorian local date and time.
	*   * year is from 0 to 9999.
	*   * month is from 1 to 12.
	*   * day is from 1 to 31.
	*   * hour is from 0 to 23.
	*   * minute is from 0 to 59.
	*   * second is from 0 to 59.
	*   * millisecond is from 0 to 999.
	*   * microsecond is from 0 to 999.
	*********************************************************/
	LocalDateTime(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microsecond = 0);

	/********************************************************
	* Creates a LocalDateTime for the given Gregorian date and time in the
	* time zone denoted by the time zone differential in tzd.
	*   * tzd is in seconds.
	*   * year is from 0 to 9999.
	*   * month is from 1 to 12.
	*   * day is from 1 to 31.
	*   * hour is from 0 to 23.
	*   * minute is from 0 to 59.
	*   * second is from 0 to 59.
	*   * millisecond is from 0 to 999.
	*   * microsecond is from 0 to 999.
	*********************************************************/
	LocalDateTime(int tzd, int year, int month, int day, int hour, int minute, int second, int millisecond, int microsecond);
	

	/********************************************************
	* Creates a LocalDateTime from the UTC time given in dateTime,
	* using the time zone differential of the current time zone.
	*********************************************************/
	LocalDateTime(const DateTime& dateTime);

	/**********************************************************
	* Creates a LocalDateTime from the UTC time given in dateTime,
	* using the given time zone differential. Adjusts dateTime
	* for the given time zone differential.
	**********************************************************/
	LocalDateTime(int tzd, const DateTime& dateTime);

	/**********************************************************
	* Creates a LocalDateTime from the UTC time given in dateTime,
	* using the given time zone differential. If adjust is true, 
	* adjusts dateTime for the given time zone differential.
	**********************************************************/
	LocalDateTime(int tzd, const DateTime& dateTime, bool adjust);

	/**********************************************************
	*Creates a LocalDateTime for the given Julian day in the local time zone.
	**********************************************************/
	LocalDateTime(double julianDay);

	/**********************************************************
	* Creates a LocalDateTime for the given Julian day in the time zone
	* denoted by the time zone differential in tzd.
	**********************************************************/
	LocalDateTime(int tzd, double julianDay);

	/**********************************************************
	* Copy constructor. Creates the LocalDateTime from another one.
	**********************************************************/
	LocalDateTime(const LocalDateTime& dateTime);
		
	/**********************************************************
	* Destroys the LocalDateTime.
	**********************************************************/
	~LocalDateTime();
		
	/**********************************************************
	* Assigns another LocalDateTime.
	**********************************************************/	
	LocalDateTime& operator = (const LocalDateTime& dateTime);
		
	/**********************************************************
	* Assigns a timestamp
	**********************************************************/	
	LocalDateTime& operator = (const Timestamp& timestamp);
		
	/**********************************************************
	* Assigns a Julian day in the local time zone.
	**********************************************************/	
	LocalDateTime& operator = (double julianDay);
		
	/**********************************************************
	* Assigns a Gregorian local date and time.
	*   * year is from 0 to 9999.
	*   * month is from 1 to 12.
	*   * day is from 1 to 31.
	*   * hour is from 0 to 23.
	*   * minute is from 0 to 59.
	*   * second is from 0 to 59.
	*   * millisecond is from 0 to 999.
	*   * microsecond is from 0 to 999.
	**********************************************************/	
	LocalDateTime& assign(int year, int month, int day, int hour = 0, int minute = 0, int second = 0, int millisecond = 0, int microseconds = 0);


	/**********************************************************
	* Assigns a Gregorian local date and time in the time zone denoted by
	* the time zone differential in tzd.
	*   * tzd is in seconds.
	*   * year is from 0 to 9999.
	*   * month is from 1 to 12.
	*   * day is from 1 to 31.
	*   * hour is from 0 to 23.
	*   * minute is from 0 to 59.
	*   * second is from 0 to 59.
	*   * millisecond is from 0 to 999.
	*   * microsecond is from 0 to 999.
	**********************************************************/	
	LocalDateTime& assign(int tzd, int year, int month, int day, int hour, int minute, int second, int millisecond, int microseconds);

	/**********************************************************
	* Assigns a Julian day in the time zone denoted by the
	* time zone differential in tzd.
	**********************************************************/	
	LocalDateTime& assign(int tzd, double julianDay);

	/**********************************************************
	* Swaps the LocalDateTime with another one.
	**********************************************************/	
	void swap(LocalDateTime& dateTime);
		
	/**********************************************************
	* @return the year.	
	**********************************************************/	
	int year() const;

	/**********************************************************
	* @return the month (1 to 12).
	**********************************************************/	
	int month() const;

	/**********************************************************
	* @return the week number within the year.
	* FirstDayOfWeek should be either SUNDAY (0) or MONDAY (1).
	* The returned week number will be from 0 to 53. Week number 1 is the week 
	* containing January 4. This is in accordance to ISO 8601.
	* 
	* The following example assumes that firstDayOfWeek is MONDAY. For 2005, which started
	* on a Saturday, week 1 will be the week starting on Monday, January 3.
	* January 1 and 2 will fall within week 0 (or the last week of the previous year).
	*
	* For 2007, which starts on a Monday, week 1 will be the week starting on Monday, January 1.
	* There will be no week 0 in 2007.
	**********************************************************/		
	int week(int firstDayOfWeek = DateTime::MONDAY) const;

	/**********************************************************
	* @return the day within the month (1 to 31).
	**********************************************************/	
	int day() const;

	/**********************************************************
	* @return the weekday (0 to 6, where
	* 0 = Sunday, 1 = Monday, ..., 6 = Saturday).
	**********************************************************/		
	int dayOfWeek() const;

	/**********************************************************
	* @return the number of the day in the year.
	* January 1 is 1, February 1 is 32, etc.
	**********************************************************/	
	int dayOfYear() const;
	
	/**********************************************************
	* @return the hour (0 to 23).
	**********************************************************/	
	int hour() const;

	/**********************************************************
	* @return hour (0 to 12).
	**********************************************************/		
	int hourAMPM() const;

	/**********************************************************
	* @return true if hour < 12;
	**********************************************************/	
	bool isAM() const;
		
	/**********************************************************
	* @return true if hour >= 12.
	**********************************************************/	
	bool isPM() const;

	/**********************************************************
	* @return the minute (0 to 59).
	**********************************************************/	
	int minute() const;

	/**********************************************************
	* @return the second (0 to 59).
	**********************************************************/
	int second() const;
	
	/**********************************************************
	* @return the millisecond (0 to 999)
	**********************************************************/	
	int millisecond() const;

	/**********************************************************
	* @return the microsecond (0 to 999)
	**********************************************************/	
	int microsecond() const;

	/**********************************************************
	* @return the Julian day for the date.
	**********************************************************/	
	double julianDay() const;

	/**********************************************************
	* @return the time zone differential.
	**********************************************************/	
	int tzd() const;

	/**********************************************************
	* @return the UTC equivalent for the local date and time.
	**********************************************************/		
	DateTime utc() const;

	/**********************************************************
	* @return the date and time expressed as a Timestamp.
	**********************************************************/	
	Timestamp timestamp() const; 

	/**********************************************************
	* @return the UTC equivalent for the local date and time.
	**********************************************************/	
	Timestamp::UtcTimeVal utcTime() const;


	bool operator == (const LocalDateTime& dateTime) const;	
	bool operator != (const LocalDateTime& dateTime) const;	
	bool operator <  (const LocalDateTime& dateTime) const;	
	bool operator <= (const LocalDateTime& dateTime) const;	
	bool operator >  (const LocalDateTime& dateTime) const;	
	bool operator >= (const LocalDateTime& dateTime) const;	

	LocalDateTime  operator +  (const Timespan& span) const;
	LocalDateTime  operator -  (const Timespan& span) const;
	Timespan       operator -  (const LocalDateTime& dateTime) const;
	LocalDateTime& operator += (const Timespan& span);
	LocalDateTime& operator -= (const Timespan& span);

protected:
	LocalDateTime(Timestamp::UtcTimeVal utcTime, Timestamp::TimeDiff diff, int tzd);
	
	void determineTzd(bool adjust = false);

		
	void adjustForTzd();
		
	std::time_t dstOffset(int& dstOffset) const;
	
private:
	DateTime _dateTime;
	int      _tzd;
	
	friend class DateTimeFormatter;
	friend class DateTimeParser;
};


//
// inlines
//
inline int LocalDateTime::year() const
{
	return _dateTime.year();
}


inline int LocalDateTime::month() const
{
	return _dateTime.month();
}


inline int LocalDateTime::week(int firstDayOfWeek) const
{
	return _dateTime.week(firstDayOfWeek);
}


inline int LocalDateTime::day() const
{
	return _dateTime.day();
}

	
inline int LocalDateTime::dayOfWeek() const
{
	return _dateTime.dayOfWeek();
}


inline int LocalDateTime::dayOfYear() const
{
	return _dateTime.dayOfYear();
}


inline int LocalDateTime::hour() const
{
	return _dateTime.hour();
}

	
inline int LocalDateTime::hourAMPM() const
{
	return _dateTime.hourAMPM();
}


inline bool LocalDateTime::isAM() const
{
	return _dateTime.isAM();
}


inline bool LocalDateTime::isPM() const
{
	return _dateTime.isPM();
}

	
inline int LocalDateTime::minute() const
{
	return _dateTime.minute();
}

	
inline int LocalDateTime::second() const
{
	return _dateTime.second();
}

	
inline int LocalDateTime::millisecond() const
{
	return _dateTime.millisecond();
}


inline int LocalDateTime::microsecond() const
{
	return _dateTime.microsecond();
}


inline double LocalDateTime::julianDay() const
{
	return _dateTime.julianDay();
}


inline int LocalDateTime::tzd() const
{
	return _tzd;
}


inline Timestamp LocalDateTime::timestamp() const
{
	return Timestamp::fromUtcTime(_dateTime.utcTime());
}


inline Timestamp::UtcTimeVal LocalDateTime::utcTime() const
{
	return _dateTime.utcTime() - ((Timestamp::TimeDiff) _tzd)*10000000;
}


inline void LocalDateTime::adjustForTzd()
{
	_dateTime += Timespan(((Timestamp::TimeDiff) _tzd)*Timespan::kSECONDS);
}


inline void swap(LocalDateTime& d1, LocalDateTime& d2)
{
	d1.swap(d2);
}


} 


#endif 
